The primary goal and objective of this project is to develop and validate the LEV-VAD with sufficient results and documentation to submit an Investigational Device Exemption application to the FDA to obtain approval for clinical trials. We propose to begin testing and validating our present designed and manufactured device through in vitro characterization in a series of well planned and executed steps. These steps include utilizing several computer programs selected to optimize the design components and these functions and performance simulation studies. The LEV-VAD will then have performance curves and well characterized in mock circulations where both the motor and electromagnetic bearing controllers will be optimized to operate the pump within the anticipated ranges in vivo. After preliminary results of verification the device will be implanted into a series of healthy calves for up to six hours to assure the anatomic fit and assess function in the in fully instrumented calves. In a later series of instrumented calves living up to two months, the cardiovascular system will be perturbed with drugs and removing and/or adding volumes and rapid heart rate. Implants will be done for longer durations in both instrumented and noninstrumented experiments. After the design and well-characterized prototype II are verified, the design will be frozen. Ten of these devices will be placed on an FDA-approved test circuit and test protocols for one year to demonstrate reliability of the pump and its controller. A major effort will be to develop a responsive physiologic controller utilizing first monitoring the axial forces on the impeller (power to the electronic bearings), in combination with the power delivered to the motor. Preliminary studies demonstrated that the readily available power for the levitation bearing and motor power can be used for a very sensitive controller. If a robust responsive controller cannot be developed with these two basic parameters the heart rate and/or the signal from the transonic flow meter will be incorporated into the algorithm. There are a large number of congestive heart failure patients unlikely to receive a donor heart. The existing VADs have a high rate of mechanical failure and thromboemboli. Our design targets destination therapy for recipients with a device that could provide a 20-year life extension. We have a high level of confidence that at the completion of these proposed studies we will know the application and limitations of the LEV-VAD as a destination therapy device.